11.23.2010

bp's science: how baking powder and soda make things rise (v.1)

Jess and I have recently been watching Top Chef Just Desserts. I am pretty amazed at the contestants' skills. No recipes! Make an anniversary cake in 2 hours! Build a dress out of sugar! In the show, the pastry chefs are always talking about rising ingredient ratios and how hard it is to make sure they are correct. This got me thinking about rising ingredients.

Baking soda and baking powder are two biggies. They look the same, but how are they different? And how do they work? Baking soda is sodium bicarbonate and that's it. Baking powder has sodium bicarbonate in it, but it is also combined with some other stuff, one of that some being an acidic ingredient. This leads us to how the rising agents work. When sodium bicarbonate reacts with an acidic ingredient the chemical reaction gives off carbon dioxide causing your cake, cookies, or pancakes to rise. When you use baking soda in a recipe, you must add an acidic ingredient, something like buttermilk, sour cream, chocolate, so the reaction can happen. When using baking powder, you must add moisture to your recipe to start the reaction, but it will happen on it's own.

Take a look at a chocolate chip cookie recipe versus a sugar cookie recipe. The prior uses baking soda, the other, baking powder. Interesting. Now about correct ratios, I haven't figured that out yet. I'll stick to my recipes for the time being.